1. Field of the Invention
The present invention relates to control architecture of an optical pickup unit (OPU) within an optical storage device, and more particularly, to a method for reducing a number of input terminals of an automatic power control (APC) circuit, and to an associated APC circuit.
2. Description of the Related Art
According to the related art, a conventional optical storage device is equipped with an OPU for accessing data on an optical storage medium. For example, the optical storage medium can be an optical disc such as a Compact Disc (CD), a CD-Read Only Memory (CD-ROM), or a Digital Versatile Disc (DVD). In order to control the laser poser of at least one laser diode positioned in the OPU, a conventional APC circuit is required within the conventional optical storage device. In practice, the conventional APC circuit can be implemented as a chip, in order to reduce the overall size of the conventional optical storage device. As a result, the chip size of the conventional APC circuit may be an important issue. Typically, a manufacturer of the conventional optical storage device is willing to utilize chips of smaller sizes.
Please note that decreasing the chip size of the conventional APC circuit may be helpful on reducing the associated costs. However, in a situation where the chip size is decreased, the problem of insufficient space for the input/output (I/O) terminals of the conventional APC circuit may occur. Thus, regarding implementation of the control architecture of the OPU within the optical storage device, a novel method is required for reducing the total number of I/O terminals.